pneumoperitoneum
/ˌnjuːməʊˌpɛrɪtəˈniːəm/Medicine
noun
1The presence of air or gas in the peritoneal cavity (usually as a result of perforation of a hollow viscus).
2More fully artificial pneumoperitoneum. The deliberate introduction of air or gas into the peritoneal cavity, as a diagnostic or therapeutic procedure (now chiefly as an aid to laparoscopy); the condition created by this.
Origin
Late 19th century. From pneumo- + peritoneum.